1. Field of the Invention
The present invention relates to an inflator for a safety system of an automotive vehicle, and particularly, to an improvement in a dual type inflator device where a hybrid-type inflator and a pyro-type inflator are combined.
2. Background of the Prior Art
Inflators of various designs and configurations have been invented for an air bag module equipped in a vehicle. When an inflator is activated, gas component is generated for inflating an air bag. Inflators can generally be classified into different groups or types. A hybrid-type inflator includes pressurized gas stored, which acts with a gas generated by inflammable propellant to generate gas component for filling the air bag. On the other hand, in a pyro-type inflator, the entire gas that fills an air bag a propellant gas generated a solid gas generating propellant composition.
Among conventional inflator systems, a system where at least two inflators are assembled has been known. That is, inflator systems of a plurality of inflators including a dual type have been developed in various manner.
For deployment system in a dual type inflator device, various structures have been proposed in consideration of factors such as ages and/or sizes of vehicle occupants and/or positions of the vehicle occupants in a vehicle. In a known system, a plurality of gas generating units for inflating an air bag can selectively be activated. Such at least two units are activated when a relatively increased pressure should be provided in the air bag.
In systems of another prior art, such as U.S. Pat. Nos. 3,868,124, 3,972,545, 5,219,178, 5,351,988, and U.S. Pat. No. 5,564,743, a dual type inflator device has been proposed where a hybrid-type inflator is connected at its gas outlet with a pyro-type inflator having a size smaller than the hybrid-type inflator.
However, in the conventionally proposed dual type inflator device, when respective inflators have different activation timings, that is, when activation of one of the inflators is delayed from that of the other, light-emitting phenomenon, appearing like a lantern, sometimes occurs in the air bag, which is required to be eliminated.